AGENT SETUP
Set up your coding agent for custom domains
One plugin teaches your agent our API and connects it to your account. It can then build your custom domains integration and manage your customers' domains, in Claude Code, Cursor, Codex and more.
See what the prompt saysHide the prompt
Set up SaaS Custom Domains (https://saascustomdomains.com) for me in this agent.
1. If you support plugins, install the SaaS Custom Domains plugin from https://github.com/saas-custom-domains/skills. It adds the saas-custom-domains skill and the MCP server. For example:
- Claude Code: claude plugin marketplace add saas-custom-domains/skills, then claude plugin install saas-custom-domains@saas-custom-domains
- Codex: codex plugin marketplace add saas-custom-domains/skills, then install SaaS Custom Domains from /plugins
- Devin: devin plugins install saas-custom-domains/skills
2. Otherwise, install the skill with: npx skills add https://github.com/saas-custom-domains/skills
and add this remote MCP server (Streamable HTTP) to your MCP config: https://mcp.saascustomdomains.com/mcp
3. Tell me how to sign in to the MCP server. It uses OAuth, so I sign in with my SaaS Custom Domains account. Never ask for my password. If you need an API token instead, ask me to create one at https://app.saascustomdomains.com/api_tokens and to put it in the SCD_API_TOKEN environment variable.
4. Step-by-step instructions for each agent: https://saascustomdomains.com/agent-setupPICK YOUR AGENT
Step-by-step setup for your agent
Each guide has the exact commands and config files, how to sign in, and fixes for that agent's common problems.
Claude Code
Anthropic
One plugin adds the skill and the MCP server. Sign in from /mcp.
- Plugin
- Sign in
Cursor
Anysphere
Add the MCP server to mcp.json and the skill with npx skills.
- MCP config
- Sign in or token
Codex
OpenAI
Add the marketplace, then install the plugin from /plugins.
- Plugin
- Sign in or token
VS Code
Microsoft · GitHub Copilot
Install the plugin from source. VS Code signs you in when it connects.
- Plugin
- Sign in or token
Windsurf
Cognition · now Devin Desktop
Install the plugin with devin plugins, or add the server to mcp_config.json.
- Plugin
- Sign in or token
Cline
Cline
Add the server from Remote Servers with Streamable HTTP.
- MCP config
- Sign in or token
Claude
Anthropic
Add a custom connector and sign in. It reaches Claude Code too.
- Connector
- Sign in
ChatGPT
OpenAI
Add a custom MCP server as a plugin and sign in with OAuth.
- Plugin
- Sign in
SKILL VS MCP
Which one do I need?
They do different jobs. The skill is knowledge for writing code; the MCP server is access to your account. The plugin installs both.
Build
The skill
Teaches your coding agent how to add custom domains to your app with our API.
- Writing the code that adds, checks and removes customer domains
- Showing customers the right DNS records
- Verifying proxied requests and webhooks
- Works without an account, against scd-mock
“Add custom domains to this app with SaaS Custom Domains.”
Operate
The MCP server
Lets your agent or assistant work in your SaaS Custom Domains account.
- Adding a customer's domain and getting its DNS records
- Finding out why a domain isn't live yet
- Managing redirects, rules and cache purges
- Reading traffic and analytics for a domain
“Why isn't shop.northpeak.com live yet?”
WHAT YOUR AGENT GETS
Everything an agent needs to work with custom domains
The skill
A single SKILL.md that follows the open Agent Skills format. Agents load it when you work on custom domains, and it covers:
- One-time setup: the upstream your custom domains forward to
- Adding a customer's domain, with the options for root, www and wildcard domains
- The DNS records to show your customer, including Cloudflare users
- Knowing when a domain is live, with webhooks or polling
- Serving proxied requests: the auth token check, then the X-Served-For host
- Changing or removing a domain, and testing locally with scd-mock
Read SKILL.md or install it from GitHub with npx skills add https://github.com/saas-custom-domains/skills.
The MCP server
A remote server at https://mcp.saascustomdomains.com/mcp over Streamable HTTP, so there's nothing to install. Clients sign in with your SaaS Custom Domains account, or send an API token. Tools take hostnames like app.customer.com, not IDs.
Look up
list_accountslist_upstreamslist_custom_domainsget_custom_domainlist_redirectslist_ruleslist_custom_certificates
Change
create_upstreamadd_custom_domainverify_dnspurge_cachecreate_redirectupdate_redirectcreate_ruleupdate_rulereorder_rules
Analytics (Domain Analytics add-on)
get_traffic_statsget_web_analyticsget_analytics_over_timeget_analytics_breakdown
Delete (your client asks first)
delete_custom_domaindelete_redirectdelete_ruledelete_custom_certificatedelete_upstream
The CLI
Terminal agents like Claude Code and Codex, your scripts and CI can use our open-source CLI. It calls the same API, takes hostnames, prints JSON with --json, and exits with documented codes.
npx @saas-custom-domains/cli domains add app.customer.comSign in with scd auth login, or set SCD_API_TOKEN. CLI docs
Docs for agents
- docs.saascustomdomains.com/llms.txtIndex of the API docs, written for agents.
- llms-full.txtThe full API reference in one markdown file.
- openapi.jsonOpenAPI spec for the REST API.
- auth.mdHow agents get API credentials, and what they can do with them.
- Agent skills indexDiscovery file that lists the skill and its digest.
- saascustomdomains.com/llms.txtIndex of this site: pricing, guides and product pages.
Every page on saascustomdomains.com also returns markdown when a request sends Accept: text/markdown.
Test locally with scd-mock
scd-mock runs our API and proxy on your machine, for development and CI. No account, real DNS or TLS needed.
docker run --rm -p 4010:4010 -p 4080:4080 \
-e SCD_MOCK_UPSTREAM_HOST=host.docker.internal \
ghcr.io/saas-custom-domains/scd-mock:latestThe API is at http://localhost:4010/api/v1 with the token scd_test_token. Domains ending in .localhost go live after 2 seconds, so http://acme.localhost:4080/ reaches your app through the mock proxy.
EXAMPLE APPS
A guide and a runnable app for your framework
Point your agent at the example for your stack. Each one is a small multi-tenant app with custom domains that runs locally with scd-mock.
FAQ
Questions about agent setup
Do I need the skill, the MCP server, or both?
The skill helps your agent write the code that integrates custom domains into your app. The MCP server lets it work in your account: add domains, check DNS, read traffic. Most teams use both, and the plugin installs both.
What can my agent do in my account?
Anything you can, in all of your accounts. Delete tools are marked as destructive, so most clients ask you before running them. Treat an agent like a teammate you give access to.
How do I disconnect an agent?
Each connected client gets its own API token under Settings » API. Delete it to disconnect that client.
Does it cost extra?
No. There's no charge for the plugin, the skill or MCP tool calls. You pay per domain, as usual, and we don't cap API requests.
Do I need an account?
The skill and scd-mock work without one, so you can build and test your integration first. Connecting the MCP server needs an account; the free trial is enough.
Can my agent use a CLI instead of the MCP server?
Yes. Agents that run terminal commands, like Claude Code and Codex, can use npx @saas-custom-domains/cli with --json. It does the same things as the MCP tools, and it also works in scripts, CI and against scd-mock. See the CLI docs.
Can the MCP server use scd-mock?
No. The MCP server always works with your real account. For local development and tests, point your app's API calls at scd-mock; the skill explains how.
My agent isn't listed. Will it work?
Most likely. Any agent that supports Agent Skills can install the skill with npx skills add, and any MCP client that supports Streamable HTTP can connect to https://mcp.saascustomdomains.com/mcp by signing in or with an API token. See the MCP docs.
Give your agent your custom domains
Start your free trial, then connect your agent by signing in.